Federer again stretched to 4 sets at French Open

Even though Roger Federer was again far from his best, he still managed to advance at the French Open.

Novak Djokovic and Victoria Azarenka, the top-ranked man and woman, had no such issues.

Federer, the 2009 champion at Roland Garros, was pushed to four sets Friday for the second straight match before defeating Nicolas Mahut of France 6-3, 4-6, 6-2, 7-5.

"I think for bigger guys it's about, if you're able to move them around enough and they have to defend time and time again, this is maybe where you can expose some of their weaknesses, potentially," Federer said. "I thought he did well. (I) struggled a little bit, but overall obviously I'm happy I came through."

With the win, Federer improved his record number of Grand Slam match wins to 235. The 16-time Grand Slam champion is trying to become the first man over 30 years old to win a major title since Andre Agassi in 2003 at the Australian Open.

For Mahut, it was the first time he has ever won a set against Federer in four matches.

"I was believing in it. I was maybe a bit nervous going into that center court, but this went well," Mahut said. "But I'm disappointed, because you always want to do better. Disappointed I didn't win that fourth set."

Azarenka reached the fourth round in the woman's draw, while Maria Sharapova advanced to the third round. But the big surprises came early in the day when third-seeded Agnieszka Radwanska and 2008 French Open champion Ana Ivanovic were eliminated.

American teen Sloane Stephens also advanced to the fourth round, beating Mathilde Johansson of France 6-3, 6-2. Of the eight teenagers in this year's draw, the 19-year-old Stephens was the only one to even reach the third round.

"I'm excited because now I'm going to have more Twitter followers," Stephens said.

Three days after scoring a "double bagel" in the first round, the second-seeded Sharapova defeated Ayumi Morita of Japan 6-1, 6-1.

"I really wanted to try to get her on the move. I thought I played well, aggressive, moved in when I had to," Sharapova said. "With every round I'm going to be playing tougher opponents, and that's when you really want to kind of step it up and raise your level. That's what I'll try to do in the next round."

Sharapova has won three major titles in her career, but she still needs to win at Roland Garros to complete a career Grand Slam. Last year, she lost in the semifinals at the French Open.

Two days after eliminating seven-time Grand Slam champion Venus Williams, Radwanska was routed by 2009 French Open champion Svetlana Kuznetsova 6-1, 6-2.

On Court Philippe Chatrier, the 23-year-old Pole didn't look anything like the player who overwhelmed Williams in straight sets on Wednesday.

"She was just playing very aggressive on both sides," Radwanska said of Kuznetsova. "She just had (an) answer for everything I was trying to do."

Radwanska has been having a stellar year on tour, winning three titles and moving up to a career-high No. 3 ranking last month. But she is the only player in the top 10 who has never reached a Grand Slam semifinal.

"It's always disappointing when losing in the first week of a Grand Slam, that's for sure," Radwanska said. "Today I didn't play bad, she was just playing unbelievable."

Against Kuznetsova, however, Radwanska has struggled. She is now 3-10 against the Russian, including her only two losses in tournament finals.

Before Friday's match, Radwanska had been 38-7 in 2012, with six of those losses coming against top-ranked Victoria Azarenka.

Kuznetsova, who also won the U.S. Open in 2004, has struggled since winning the title at Roland Garros three years ago, only reaching one Grand Slam quarterfinal.

"I try to play more forehands. I try to dictate. I play more speed," Kuznetsova said of her play Friday. "This is the game I was playing when I won U.S. Open and I won the French Open."

Also in the third round, the 13th-seeded Ivanovic lost to Sara Errani of Italy 1-6, 7-5, 6-3.

The former top-ranked player committed 37 of her 40 unforced errors in the final two sets. Errani had only 18.